Prompt

A table of local-anaesthetic additives (adrenaline, bicarbonate, clonidine, dexmedetomidine, dexamethasone, morphine, hyaluronidase) with their effect and main caution.

Stimulus

You are shown a table of common local-anaesthetic additives — adrenaline, sodium bicarbonate, clonidine, dexmedetomidine, dexamethasone, morphine and hyaluronidase — together with their principal effect and their main caution. Discuss the rationale, effects and safe use of these adjuvants.

References9Show

[1]Kirksey MA, et al. Local Anesthetic Peripheral Nerve Block Adjuvants for Prolongation of Analgesia: A Systematic Qualitative Review PLoS One, 2015.PMID 26355598
[2]Bailard NS, et al. Additives to local anesthetics for peripheral nerve blocks: Evidence, limitations, and recommendations Am J Health Syst Pharm, 2014.PMID 24534592
[3]Hong B, et al. Consistent analgesic effect of intravenous dexamethasone on rebound pain after brachial plexus block: a causal machine learning approach Korean J Pain, 2026.PMID 42357812
[4]Rawal N Intrathecal opioids for the management of post-operative pain Best Pract Res Clin Anaesthesiol, 2023.PMID 37321761
[5]Palleschi GT, et al. Respiratory depression after administration of single-dose neuraxial morphine for post-cesarean delivery analgesia: a retrospective cohort study Int J Obstet Anesth, 2022.PMID 36137450
[6]Eggleston ST, Lush LW Understanding allergic reactions to local anesthetics Ann Pharmacother, 1996.PMID 8826570
[7]Mohankumar A, Rajan M Role of hyaluronidase as an adjuvant in local anesthesia for cataract surgery Indian J Ophthalmol, 2023.PMID 37417102
[9]Charuluxananan S, Somboonviboon W, Kyokong O, et al. Ondansetron for treatment of intrathecal morphine-induced pruritus after cesarean delivery. Reg Anesth Pain Med, 2000.PMID 11009242
[13]Antares Pharma Inc. HYLENEX RECOMBINANT (HYALURONIDASE) INJECTION, SOLUTION — prescribing information. DailyMed, 2026.Source

Stimulus

References9Show

[1]Kirksey MA, et al. Local Anesthetic Peripheral Nerve Block Adjuvants for Prolongation of Analgesia: A Systematic Qualitative Review PLoS One, 2015.PMID 26355598
[2]Bailard NS, et al. Additives to local anesthetics for peripheral nerve blocks: Evidence, limitations, and recommendations Am J Health Syst Pharm, 2014.PMID 24534592
[3]Hong B, et al. Consistent analgesic effect of intravenous dexamethasone on rebound pain after brachial plexus block: a causal machine learning approach Korean J Pain, 2026.PMID 42357812
[4]Rawal N Intrathecal opioids for the management of post-operative pain Best Pract Res Clin Anaesthesiol, 2023.PMID 37321761
[5]Palleschi GT, et al. Respiratory depression after administration of single-dose neuraxial morphine for post-cesarean delivery analgesia: a retrospective cohort study Int J Obstet Anesth, 2022.PMID 36137450
[6]Eggleston ST, Lush LW Understanding allergic reactions to local anesthetics Ann Pharmacother, 1996.PMID 8826570
[7]Mohankumar A, Rajan M Role of hyaluronidase as an adjuvant in local anesthesia for cataract surgery Indian J Ophthalmol, 2023.PMID 37417102
[9]Charuluxananan S, Somboonviboon W, Kyokong O, et al. Ondansetron for treatment of intrathecal morphine-induced pruritus after cesarean delivery. Reg Anesth Pain Med, 2000.PMID 11009242
[13]Antares Pharma Inc. HYLENEX RECOMBINANT (HYALURONIDASE) INJECTION, SOLUTION — prescribing information. DailyMed, 2026.Source

Local anaesthetic adjuvants

Stimulus

Local anaesthetic adjuvants

Stimulus